An illuminated picture frame, or edge-lit backlighting panel, is not new. Edge-lit backlighting panels are often utilized in consumer electronic products. Illuminated picture frames have been previously contemplated and invented; however many of the prior embodiments comprise complex frame structures, bulky or nonintegrated battery attachments, and antiquated mounting mechanisms.
For example, U.S. Pat. No. 4,819,353, issued to Gluckman, Cohen, and Ratzlaff, discloses an illuminated picture frame that comprises an outer frame structure with an interior matte, wherein the frame structure and matte are utilized to block or conceal the light source that illuminates the assembly. Because the frame structure and matte are located at the exterior edges of the main body, this type of construction will not allow edge-to-edge illumination as described below in the present invention. Additionally, the batteries for the '353 Patent are located within a battery housing that is built into the support leg that mounts to the back wall of the assembly. Because the support leg extends outwardly from the back wall of the main body, the total assembly is too cumbersome and bulky to mount to a wall in a low profile; therefore the '353 Patent is limited and may only be utilized as a table or countertop display.
Likewise, U.S. Pat. Pub. No. 20100088941 by Shiqi Zhu also discloses an illuminated picture frame that comprises an outer frame structure that is configured to block or conceal the light source, or LED strip, that illuminates the assembly. However, like the previous prior art, a construction that employs a frame structure at the exterior edges of the main body will not allow edge-to-edge illumination as described below in the present invention. Additionally, the batteries of the '941 Publication are built into a rear-mounted display stand battery housing, so again the total construction is too bulky to mount on a wall in a low profile; therefore, the invention is limited and may only be utilized as a table or countertop display.
U.S. Pat. No. 5,657,563 by Lane, and U.S. Pat. No. 7,942,542 by Dunn, also disclose illuminated picture frame embodiments that employ outer frame structures to block or conceal the primary light sources, and batteries that are built into auxiliary assemblies that prevent flat wall mounting and limit the inventions to table or countertop applications. For example, the '563 Patent incorporates the batteries into the display stand assembly that mounts to the back wall of the main body; and the '542 Patent positions the batteries in the bottom of a condiment, straw, or napkin holder.
Finally, U.S. Pat. Pub. No. 20060285358 by Chen and Shen, and U.S. Pat. Pub. No. 20140223787 by Richmond and Pesek, disclose illuminated picture frames that employ one or more LED light strips and an outer frame structure to block or conceal the light source origin points. These two references do not to employ a thick, translucent, milky-white diffusion layer, as described below in the present invention. The '358 and '787 Publications rely on the strategic placement of an outer frame structure to block or conceal LED “hotposts”. Additionally, these references offer no wall mounting option, although the '787 Publication does disclose a front surface adhesive mounting system, wherein the front surface of the assembly mounts to a window, and the image or artwork is viewed through the window.
Recent advancements in the development of more efficient and smaller light-emitting diodes (LEDs), and thinner and more compact Lithium-ion batteries warrant a new approach to developing a thin, frameless (edge-to-edge illuminated), elegant lighting assembly that draws less power, while additionally providing a means for employing a removable/exchangeable photograph or artwork overlay.
Constructing a thin, power-efficient lighting assembly with edge-to-edge illumination is a difficult task. One big design challenge that arises while constructing a thin frameless lighting configuration is how to avoid “hotspots” that occur along the linear edge where the LEDs shine into the light guide panel. Another challenge is providing a low profile design that can be mounted to a wall with quick and easy removal of the ultra-thin rechargeable battery from the backside of the assembly.
There are two main ways to backlight a photo or artwork lighting display. The first way is to mount an array of LEDs in even rows on the bottom layer of the lighting assembly, then a uniform air-gap is provided above the LEDs to diffuse the “hotspots” where the LEDs are located; and finally, an additional diffusion layer may be oriented above the uniform air-gap to further diffuse the areas where the “hotspots” are located. This type of configuration requires an air-gap that increases the thickness of the lighting assembly. Light boxes typically use this type of lighting construction that employs a uniform air-gap. This design sufferes from at least two drawbacks. First, the additional thickness that is added to the lighting unit makes it impractical for low-profile displays of art, that would be common in a residence. And second, the successive rows of LEDs consume significantly more power than a single LED light strip, making such a device impractical for use with battery power.
The second way to backlight a photograph or artwork display is to employ an LED light strip that shines directly into at least one edge of a light guide panel that is configured as a mid-layer member of the light tile assembly. However, because there is no uniform air-gap to diffuse the LEDs, the issue of LED “hotspots” remains a problem that still needs to be solved. The common way to deal with LED “hotspots” in a low-profile construction (as prior art demonstrates) is to print a black border or frame on a layer above the LEDs so the border or frame blocks out or conceals the LED “hotspots.” This type of LED “hotspot” blocking is common and conventional, indeed this is the solution of the prior art discussed above. But this has a significant drawback that it cannot provide frameless, edge-to-edge illumination.
Therefore, there exists a need for a thin, frameless, low-profile light tile for illuminating a photograph or artwork display that may be powered by a battery.